The NI PXI Multidevice Clock Disciplining Bundle helps you discipline the 10 MHz PXI reference clock to an external timebase such as GPS, IEEE 1588 2008 (IEC 61588:2009), or IRIG-B. This improves the synchronization quality over alternative timekeeping implementations and provides a high-quality synchronized reference clock. The bundle includes two PXI timing modules, the NI PXI-6653 and NI PXI-6682H, as well as an NI LabVIEW library that enables the functionality. The PXI-6653 features a controllable 10 MHz high-stability oscillator, and the PXI-6682H monitors the timebase. You can still take advantage of the basic functions of each module, including DDS clock generation and timestamping. The LabVIEW library monitors the phase and frequency of the 10 MHz reference, compares it to the Time Reference (GPS or other), and adjusts the oscillator to align with the timebase.
By disciplining the 10 MHz clock in multiple systems in this fashion, you can align it to remove drift and keep phase aligned to less than 6 ns standard deviation between systems. This helps you synchronize the 10 MHz clock when distances greater than 200 m prohibit the use of coaxial cables for sharing clocks and when it is more convenient to synchronize systems over an Ethernet cable (IEEE 1588). It also helps you achieve improved time synchronization.